Web sites, and other providers of information, often allow users to give feedback on the quality of the information. For example, a user may search for an article on a web site, and the article found in the search may conclude with a questionnaire allowing the user to rate the helpfulness of the article—either as helpful/unhelpful or on a numeric scale (e.g., “rate the helpfulness of this article on a scale of 1 to 5, where 1=very unhelpful and 5=very helpful”). The results of the ratings are collected, and can be provided to the publisher of the information as a gauge of the public's opinion of the information. Also, the results can be posted on the web site itself to assist other users in judging the value of the information (e.g., “40 out of 85 users found this review helpful” or “the average score for this article is 3.9 out of 5.0”).
However, these types of questionnaires have a very low response rate—often less than one percent—and the results may be difficult to interpret. “Helpfulness” of an article can have different meaning to different users (e.g., the article may not have answered the question for which the user initiated the search, but may have provided some unexpected useful information). Moreover, with numeric scales, different users tend to assign different meanings to the numbers on the scale. Experience shows that the prevalence of individual votes is skewed heavily toward the extreme high and low ends of the scale.
In addition, these questionnaires tend to ask mainly about generic issues (e.g., “Was this article helpful?” or “Did this article answer your question?”), so the results of the questionnaire do not normally tell users anything specifically relevant to the article. Also, a questionnaire indicating that users found the article “helpful” or “unhelpful” is, in effect, an anonymous assertion, made collectively by a large number of prior readers who have little stake in the credibility of the assertion.